Hi Rahul
It is stated in vSphere Documentation that you can use vMotion with VMs with RDM.
vSphere 5.5 Documentation Center - About Raw Device Mapping
Using RDMs, you can:
- Use vMotion to migrate virtual machines using raw LUNs.
If you use vMotion to migrate virtual machines with RDMs, make sure to maintain consistent LUN IDs for RDMs across all participating ESXi hosts.
RDM considerations & limitations are listed here: vSphere 5.5 Documentation Center - RDM Considerations and Limitations
FYI, related links on RDM:
VMware KB: Microsoft Clustering on VMware vSphere: Guidelines for supported configurations
VMware KB: Difference between Physical compatibility RDMs and Virtual compatibility RDMs
VMware KB: Migrating virtual machines with Raw Device Mappings (RDMs)
VMware KB: Frequently Asked Questions on VMware vSphere 5.x for VMFS-5
vSphere 5.1 - VMDK versus RDM | VMware vSphere Blog - VMware Blogs
Use RDMs for Practical Reasons and Not Performance Reasons | VMETC.com
http://www.vmware.com/files/pdf/performance_char_vmfs_rdm.pdf
Physical RDM to VMDK Migration Feature | VMware vSphere Blog - VMware Blogs
Migrating RDMs, and a question for RDM Users. | VMware vSphere Blog - VMware Blogs